200 UFE OF improvement in man,, from the oldest natural history of the old Hellenes. He calls the great world events, such as the voyage of Colaus from Samos, to beyond the pillars of Hercules, the expedition of Alexander to India, the dominion of the Romans, the spread of the Arabian religion, and the discovery of America, sudden means of increasing the knowledge of nature, especially in the life of those nations which once inhabited the shores of the Mediterranean. And, at this point, Humboldt refers to languages which each operate as a means of communication between sepa- rated nationalities, and which, by comparison with each other, by an investigation into their constitution, and the similarity of their character, assist in the study of the human races. Humboldt likes always to build his investigation on some object, in all his observations which lead him to universal subjects, and, thus,^in his description of the world in general, which is represented principally by natural, philosophical, and rarely by perceptive illustrations, he seeks some point of earth upon which he can advance contemplatively and experimentally. He takes, for this purpose, the Mediterranean Sea as the circumscribed space, round which those nations lived who prepared .the foundation for our subsequent western civilization. From these shores of the Medi- terranean he explores the course of civilization, and finds the history of the knowledge of nature advance progressively with civilization, but not proceeding from one, but from several primitive nations. In the remotest antiquity, at the extreme horizon of past historic ages, we see, contemporaneously, several bright stars from which the rays of civilization, crossing each other, have flowed on, as in Egypt, Babylon, Nineveh, Cashmere, Iran, and China. Humboldt says, on this occasion, "these central stars remind one, involuntarily, of the greater among the dazzling stars of the firmament, of the eternal stins, in space, of wMch we perceive the brilliancy of their light, but do; not know, except of a very few, their distance from our planet^'